Many people describe the medical field as a tug of war between breakthroughs and setbacks. And medical stories in 2010 were no different.
The following are nine of the most important health stories in 2010, as reported by ABC News' Medical Unit.
The immediate damage to infrastructure and the death toll seemed apparent across the poorest country in the Western Hemisphere. Although more than a billion aid dollars funnelled in to repair Haiti, many experts braced for a public-health aftershock.
And they were right.
Nearly 10 months after the January earthquake, cholera spread to many rural areas and quickly creeped into the capital city, Port-au-Prince. In just a few months, nearly a thousand Haitians died from the waterborne disease.
"What we are seeing now may be the tip of the iceberg," Dr. Georges Dubuche, adviser to Haiti's Ministry of Health, said in a news conference early October.
Many experts did not know then the extent of the epidemic.
Indeed, Cholera spread faster than many public health experts anticipated. Relief workers continue to ramp up efforts to manage the outbreak amid the more than 2,000 people who have now died from the disease.
The $938 billion health care bill will expand coverage to 32 million Americans, but many of the provisions -- with the exception of prescription drug coverage for older Americans and children who have been denied insurance because of pre-existing conditions -- are not expected to go into effect until 2014.
The U.S. Court of Federal Claims concluded in March that thimerosal -- a preservative found in some vaccines -- does not cause autism. The courts reviewed previous scientific studies and found no correlation between vaccination rates, mercury levels and the incidence of autism in children.
This so-called landmark decision followed many rulings in previous years that cited no association between vaccines and autism. Previous rulings by the court also dismissed the autism-vaccine connection. Still, it's likely there may be more cases because many parents of children with autism are unconvinced.
Indeed, the 2008 settlement for Hannah Polling became the staple case for many families of children with autism. The Polling family received compensation for Hannah's "vaccine injury" when the court settled, because, according to settlement documents, the vaccinations she received, "significantly aggravated an underlying mitochondrial disorder [...] and manifested as a regressive encephalopathy with features of autism spectrum disorder."
Many people say that regardless of the 2010 omnibus rulings, there will be more cases such as Polling's to come.
An estimated 87 million Americans are sickened by contaminated food, and 5,700 die from food-related disease each year, according to the Centers for Disease Control and Prevention. But supporters of the Food Safety Modernization Act, which has already passed in both the U.S. Senate and House of Representatives, hope greater food industry oversight by the U.S. Food and Drug Administration will change that.
Among the provisions of the bill, the FDA would have authority to order mandatory recall of tainted foods and set safety standards for raw produce, such as fresh fruit and vegetables. The agency would also increase inspections of domestic and foreign food facilities.
But many food industry companies are particularly concerned with the Tester Amendment, a part of the bill that would exempt smaller food producers and those that distribute locally.
"The consequences of inadequate food safety precautions have no boundaries as to size of operation, geography nor commodity," 19 food industry organizations said in a letter to House leaders in November 2010.
Still, both the House and Senate committees passed the bill. The bill is expected to be signed into law in early 2011 by President Obama, who has already expressed his approval of the bill.
Providing cardiopulmonary resuscitation (CPR) -- a combination of mouth-to-mouth breathing and chest compressions -- immediately after sudden cardiac arrest can double or triple a victim's chance of survival, according to the American Heart Association.
But less than one-third of those who suffer sudden cardiac arrest outside of a hospital receive CPR from a bystander.
"I think there's some fear of getting it wrong," said Dr. Richard Page, former president of the Heart Rhythm Society and current chairman of the Department of Medicine, University of Wisconsin.
But two new studies published July 2010 in the New England Journal of Medicine suggested that if you're not sure how to properly administer CPR, chest compressions alone may be as effective, if not more effective, than the traditional CPR, which calls for both chest pumping and rescue breathing.
Many studies suggest that bystanders are more willing to attempt resuscitation if mouth-to-mouth ventilations are not required.
Rescue breathing is not appropriate in all first aid situations and may waste time especially if done by someone inexperienced in traditional CPR, said Dr. Michael Sayre, associate professor of emergency medicine at Ohio State University.
"We really could save thousands of lives across the country if we could just get more people to do something simple like push hard and fast on the center of the victim's chest," Sayre said.
For a schedule of CPR classes in your area, visit the American Red Cross or the American Heart Association.
For a cheat sheet on chest compressions and CPR, visit here.
In 2008, more than 42,000 people in the United States were diagnosed with HIV. Nearly half of those infected were men who engaged in sex with other men, according to the Centers for Disease Control and Prevention.
Condom use "has already decreased due to HIV treatment being so effective," said Dr. Tom Coates, director of the UCLA program in global health.
"HIV prevention is already not working all that well among gay men," Coates said.
But daily use of the antiretroviral drug commonly known as Truvada may greatly cut the chance of getting infected with AIDS, researchers have found in a groundbreaking new study.
The study published November 2010 in the New England Journal of Medicine offered the first indication of an oral method to prevent the spread of HIV among those at high risk.
"This is an important trial that further extends the growing appreciation that antiretroviral therapy can play a vital role in controlling the HIV epidemic," said Dr. Paul Volberding, co-director of the University of California San Francisco Center for AIDS Research, who was not involved with the study.
Although the study was limited to one kind of high-risk group, further pre-exposure prophylaxis (PrEP) studies are looking at other groups at risk for transmission, including heterosexual couples and intravenous drug users. Researchers also plan to conduct a longer term follow up to the original published study beginning 2011.
For years, scientists have been able to genetically modify plants and animals. But this year, for the first time, a group of researchers successfully created the first man-made cell.
Researchers at the private firm J. Craig Venter Institute replaced the genome of a bacterium with one they wrote themselves. The cell turned into a different species than its original form and was able to live and replicate.
"[The new cell is] the first self-replicating species we've had on the planet whose parent is a computer," Dr. Craig Venter said at a news conference in May announcing the technique's success.
The so-called synthetic cell further pushed open the door to synthetic biology, combining chemicals, biology and genetics research to replicate fuels, vaccines and living organisms.
Bisphosphonates are commonly prescribed to prevent osteoporosis and make bones stronger. But an ABC News investigation found mounting evidence that for some women, taking the popular osteoporosis drug Fosamax or its generic alendronate for more than five years could cause spontaneous thigh-bone fractures.
The U.S. Food and Drug Administration announced in March that it will look into whether a link exists between the long-term use of the osteoporosis drugs and femur fractures after ABC News investigated the possible connection.
"We are seeing people just walking, walking down the steps, patients who are doing low-energy exercise," said Dr. Kenneth Egol, professor of orthopedic surgery at NYU Langone Medical Center. "Very unusual, the femur is one of the strongest bones in the body."
Egol said X-rays of some of his patients look more like an injury endured by a car accident than an otherwise minimal fall.
Many studies suggest an overall benefit from taking the medication for women who are at risk for osteoperosis. Indeed, bisphosphonates can help prevent hip and spine fractures, which for many women may lead to death.
Although bisphosphonates are generally recommended for postmenopausal women, research does not indicate how long women should be on the drug. Many doctors now recommend a five-year limit.
Many consider it science on the cutting edge: Umbilical cord blood rich in stem cells obtained once a child is born can be used to treat rare conditions and holds promise for the future. And with 4 million births in the United States each year, private cord-blood banking is a growing industry.
But an exclusive ABC News investigation found the costs of private banking outweigh the potential benefits to many families.
In their marketing material, many private banking firms tout an impressive list of 70 to 80 diseases that purportedly are treated by stem cell transplants. But research has yet to prove that stem cells from cord blood work for all of the listed conditions.
"Presently, we treat over 80 life threatening diseases," said Dr. Albert Sassoon, an obstetrician-gynecologist in New York City who spoke earlier this year at a dinner sponsored by ViaCord, a private cord-blood banking firm. "With the amount of diseases that we treat today, by the time you reach the age of 70, you'll have approximately the chance of receiving a stem cell transplant -- one in 200, one in 217."
But many experts told ABC News that the chance that anyone will benefit by their own cord blood -- which is what is stored in private cord banking -- is much lower than that.
Private storage of a newborn's umbilical cord blood can range from $2,000 to $3,000 up front, plus yearly storage fees of $85 to $125. Doctors who refer parents to private cord-blood banking are often compensated by the private company.
Public cord-blood banking is free and is entered in a public system where the cells are available to anyone who needs it. And some diseases such as leukemia, which is listed in ViaCord's marketing material as treatable by stem cell transplants, cannot be treated using the children's own cord blood because the stem cells may carry the same disease. Instead, many doctors turn to public banks for treatment.
The American Medical Association and the American Academy of Pediatrics recommend public banking over private, favoring private banking only when there is already an affected family member or a disease in the family that would benefit from a transplant.
Still, firms such as ViaCord and Cord Blood Registry are banking on many parents who believe that their child's stem cells may one day treat chronic conditions, even though many experts say it's still too early to tell.